These little cards are wonderful classroom management tools, especially in the middle school level. I print these using the business card format on colorful paper, then I have it laminated. I write the students' names in permanent marker on the front and their class number on the back of the card. Our school supplies the students with agendas which must be carried to every class, so we staple these cards to the inside front cover of their agendas. This way they always have it and never loose them(unless they lose their agendas). Students get a new card at the beginning of every quarter.
When students need a hall pass, except for seeing the nurse, that cannot wait until the end of class, they present their agenda, and I hole punch one of the smiley faces. Once they use all ten, they must either wait until the next quarter, or they can use Class Dojo points to purchase a new one. At the end of the quarter, any unused smiley faces are counted as bonus points towards their final grade.
Students really love this system and become quite thrifty about using their smiles. Very few like to end the quarter with no bonus points, and many do not want to use their Class Dojo points to buy a new card! It really cuts down on restroom or locker passes that really are not needed, and encourages them to schedule their breaks in between classes more carefully.
You can really adapt this system for any grade or subject area. Please note it was created on Microsoft Publisher---it does not transfer well to Google Docs.